COVER PHOTOLOOKING NORTHWARD AT THE HOGSBACK AREA. For
nearly 2-1/2 miles, the cliffs and promontories are composed of large
resistant blocks of chaotically mixed sandstone and volcanic rocks act
in a matrix of intensely broken and sheared siltstone. Little Hogsback,
center, and Hogsback, in the distance, are very large resistant blocks
of volcanic rocks that were left behind as the sea eroded the coastline
eastward.